join-tab.png
close-x.png

Help Shape the Future of Space Exploration

Join The Planetary Society Now  arrow.png

enews-tab.png
close-x.png

Join our eNewsletter for updates & action alerts

    Please leave this field empty
Explore

Our Sun

All the planets, moons, and smaller things in the solar system are just dust, compared to the star that they orbit; the Sun contains 99.9% of the mass of the solar system. We think of it as our source of light, but it doesn't just emit photons. The solar wind blasts fast-moving electrons, protons, and highly ionized atoms in all directions, a constant stream punctuated by ferocious coronal mass ejections. The solar wind carries with it a magnetic field wound into a tight spiral by the Sun's rotation.

The solar wind pushes outward against the interstellar medium, penning the solar system inside a bubble called the "heliosphere" that's at least 200 AU across. The twin Voyager spacecraft are now probing the heliosphere's edges. Closer to home, a fleet of spacecraft monitors the space weather generated by the Sun, warning us of its effects on Earth, from the benevolent (aurorae) to the potentially disastrous (irradiation of astronauts and damage to communications satellites and power grids).  Currently operating solar space observatories include ACE, GGS, WIND, Hinode, PICARD, RHESSI, SOHO, SDO, Solar Monitoring Observatory, and STEREO.

Latest Blog Entries about the Sun, Heliosphere, and Space Weather

Yet more planet transits

Posted by Emily Lakdawalla on 2012/06/14 11:00 CDT | 7 comments

A reader comment on Jay Pasachoff's post last week about Venus transits viewed from other planets had me asking whether transits of other planets were also interesting to astronomers. Jay provided some answers!

Read More »

Video: Comet Lovejoy entered SOHO's LASCO C3 field of view this morning!

Posted by Emily Lakdawalla on 2011/12/14 09:37 CST

An animation of comet Lovejoy entering the field of view of one of SOHO's Sun-monitoring cameras.

Read More »

Transit of Venus June 5: Why Should You Care and How to Observe

Posted by Bruce Betts on 2012/06/02 01:56 CDT | 2 comments

A rare astronomical event occurs June 5/6. Find out why you should care and how to observe it.

Read More »

Sungrazing with Lovejoy's Comet

Posted by Jason Davis on 2011/12/06 10:42 CST

Observations of the newly sighted Kreutz sungrazer comet C/2011 W3 (Lovejoy) from the ground and from SOHO (a joint NASA/ESA satellite) and STEREO (NASA's Solar Terrestrial Relations Observatory).

Read More »

Some Details About Transits of Venus

Posted by David Shortt on 2012/05/22 06:02 CDT | 2 comments

The upcoming rare transit of Venus is one step in a long dance among Earth, Venus and the Sun. Transits of Venus follow a peculiar pattern—two transits 8 years apart, then 105.5 years with no transits, then two transits 8 years apart, then 121.5 years with no transits, for a total cycle of 243 years—and thereby hangs a tale.

Read More »

Items 1 - 5 of 18  1234Next
Facebook Twitter Email RSS AddThis

Support our Asteroid Hunters

They are Watching the Skies for You!

Our researchers, worldwide, do absolutely critical work.

Asteroid 2012DA14 was a close one.
It missed us. But there are more out there.

I want to help

Save Our Science

Become a Space Advocate

We are at a crucial turning point in the history of planetary exploration.

You can help.

Together, we can get the budget we need to support our planetary endeavors and Save our Science.

We've done it before. Let's do it again.

I want to help!

Fly to an Asteroid!

Send your name and message on Hayabusa-2.

Send your name

Join the New Millennium Committee

Let’s invent the future together!

Become a Member

Connect With Us

Facebook! Twitter! Google+ and more…
Continue the conversation with our online community!

facebook.png twitter.png rss.png youtube.png flickr.png googleplus.png